D01F9/145—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments from pitch or distillation residues

D01F9/15—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments from pitch or distillation residues from coal pitch

Abstract

PURPOSE: To obtain the title fiber having a high oxygen content, oxygen functional groups on the surface, capable of excellently adsorbing a basic gas such as ammonia gas and steam by oxidizing pitch-based active carbon fiber.

CONSTITUTION: Pitch-based active carbon fiber (e.g., one prepared by purifying coal tar, distilling, subjecting the tar to polycondensation reaction to give pitch, subjecting the pitch to melt spinning, infusibilizing and activating) is heated in an oxygen atmosphere and oxidized to give the aimed fiber having ≥3wt.% oxygen content and oxygen functional groups (e.g., carbonyl group, carboxyl group or lactone group) on the surface.